Alert archive / Virginia / Freeze Watches in 2021

Freeze Watch 1, NWS Blacksburg, VA

April 20, 202123 counties in Virginia; Alleghany County, Ashe County, Watauga County, North Carolina; 4 counties in West Virginia

NWS Blacksburg, VA issued this freeze watch at Apr 20, 2021, 3:23 AM EDT for 23 counties in Virginia; Alleghany County, Ashe County, Watauga County, North Carolina; 4 counties in West Virginia. It took effect at Apr 22, 2021, 12:00 AM EDT. It was in force for .

The area

The counties it named.

The facts

Issued: Apr 20, 2021, 3:23 AM EDT (07:23 UTC)
In effect from: Apr 22, 2021, 12:00 AM EDT
Expired: Apr 21, 2021, 3:39 AM EDT
In force
Issued by: NWS Blacksburg, VA

All 30 counties

Alleghany County, NC, Ashe County, NC, Watauga County, NC, Alleghany County, VA, Bath County, VA, Bland County, VA, Botetourt County, VA, Carroll County, VA, City of Buena Vista, VA, City of Covington, VA, City of Galax, VA, City of Lexington, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Giles County, VA, Grayson County, VA, Montgomery County, VA, Pulaski County, VA, Roanoke County, VA, Rockbridge County, VA, Smyth County, VA, Tazewell County, VA, Wythe County, VA, Greenbrier County, WV, Mercer County, WV, Monroe County, WV, Summers County, WV

The radar

The Roanoke radar (KFCX), 34 km from the middle of the area, began a volume at 07:23 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 7.4 hours before the alert went out and 141 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 9 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 2320 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 23 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this freeze watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Blacksburg, VA wrote its last area forecast discussion before this freeze watch went out at Apr 20, 1:32 AM EDT, 1 hour 51 minutes earlier.

Area forecast discussion, Apr 20, 1:32 AM EDT, 1 hour 51 minutes before

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Hazardous weather outlook, Apr 19, 2:22 PM EDT, 13 hours 1 minute before

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The office that day

Everything else NWS Blacksburg, VA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 20, 2:52 PM EDT	Fire Weather Watch	RNK	Caswell, Rockingham, Stokes, Surry, Wilkes, Yadkin	13 hr

Nearby

Freeze Watches in Virginia, 2021 Freeze Watches in West Virginia, 2021 Freeze Watches in North Carolina, 2021 Every freeze watch in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.